The National Association of Realtors and Data Distribution Technologies have settled a lawsuit NAR filed in June seeking to invalidate DDT's patent.

Under the terms of the settlement, DDT has agreed to no longer enforce its patent in the real estate industry in exchange for NAR dropping its challenges against the patent. DDT received no money as part of the deal.

It’s a scenario that could qualify under “worst nightmares.” A real estate broker receives a letter accusing him or her of violating a patent over something many real estate websites do: sending an email alert when a website is updated with a property that matches a user’s desired criteria.